Preparation of ketones by dehydrocarboxylation of carboxylic acids



r Patented Sep t."30, 1 952 sures PATENT I .1 I

' M12524 PREPARATION-F KETONESIBYHDEHXDBO- 4. 7 g QA J 'P QN 1 F s mm sms,

- .mbmro. :Zettle'moyei', WiIIiam C. 'Walket,1and. e William L.\StummtBethlehem, Pa assignorsto .FoodtMachiner-y and ChemicalCorporation, ,-New Y- ork,N. .Y a corporation of Delaware No'nmwinAssessment-seminar 9,1948? Serial No. 64 ,124

. f t-1o Claims, (01. fast -tact [lhiszinvention relates tonesfrom-acarboxylic'acidsatelevated temperatures :in the presence or acatalyst. andrmore particularly to the catalyzation ofdehydrocarboxylation reactions by means of certain magnesia compoundsr-hereinafter more .iu-lly described i V A number oi ketones at thepresent time are produced; commercially, in quite satisfactoryyieldsiand at;reasonableoosts.:butvarious specific ketvnes can only'beproduced on a commercial scale by, processes "operating at extremely110w efiiciency. For example; phenyl acetone vhas been produced byreacting phenyl acetic acid andwaceticgacid inthe presenceoithoria, supported on gpumice at atemperature of about 440 1; Qnly, 45%;conversionof the; phenyl acetic acidhssbeen obtainable although the .ratio ofv the.reactantsmasbeen maintained at 1 to "2 and the space velocity has beenlimited to 0.2.

Jr-he present process is applicable to the production of ketones broadly"or to ,ketones of :all types. Aepecific object. however. is to producephenyl vacetoneby a more emcient process than that now employedcommercially and generally considered .the best method available :iorcom mercialoperation. 7 Y

Broadly considered, the process involves dehyato'the production dike-'1number, of 130 and an isnitiom-loss-Di drocarboaylating carboxylic acids.by heating-:the

acids, ,in 'the presence of a magnesia havinganiodinenumber in excess of1'5r-and an "ignition loss; on-. he ating. of .rrom 1 to, 20 Inka:preferred; procedure of the invention. the acid '(or the mixture ofacids) to beidehydrocarboxylated is v-vaporized and; continuo sly-passedover or through the catalyst in solid condition. Tem-' peratureswithin'the-range of 300 to 350 C. are

preferred, but in some instances temperatures 7 outside- 0f this. rangelead to satisfactory-results. ,.'lf.'l e inventionds :not limited tovapor phase reactions, but it :is applicable also to liquid :phasereactions, the latter being ,ieasible' for acids, of very low vo1ati1ity. When vapor phasereactions are employed, the space velocitymay be varied considerably without detrimental effect, but welccities oifrom 0.1 to 1.0 liter oi liquid 'Ieed per..-liter,of catalyst ,perhoursenerally give desirable-results. Itis not essential that'the*reaction be. carried out at atmospheric pressure and if necessary tovaporize relatively nonvolatilereactants or even volatilereactants thereaction may be carried out under reduced :atmospheric pressure. Thereaction of solid or relatively non-volatile reactants army :in:someinstances be iacilltated by thepresence 11: an innema whfma r"fixamziled' A mixture or henyl acetic .acid and acetic acid .in the"moi ratio'flo'i 1 to is wasyaporiaedpreheated, and pas'sedthroughlicontaining, active magnesia .havin velocityor 0.36 liter/liter ofcatalyst/h product obtainedwas then treatedtcrecoverthe phenyl acetoneby neutralizing any unreacted acid with a solution of sodium bicarbonateand then separating the oil andwater layers oil layer wasthen-fractionated and the collected between 21.0 {and 230";C .;.;thl ucte nelt ephen ace net amountm lected represented conversionzof adaption.yl acetic acid. :11.

The .foregoing process was; repeated slain; in differentmagnesia,.namely one thaving anlodlm, numberof l46tandan ignition lossot7 uh;- stantially the same results 'Lwere tobta ed I .A mixture of-phenyl acetic L-acid andaace'tic acid in the mol; ratio of '1 to 2: incombination with ;3:mols of acetone .was"yaporizedppreheated and passedthrough a reaction =zone containing active magnesia having an ziodine'number eoi and ;anignition loss of -7., at a velocity @01 "0.36liter/liter of catalyst/hour. I'Ihe :product was :recovered in theqsame:manneras-described inExample-J. :1 1' EMMPZeB I (A mixture of phenylacetic acidand acetic acid in the mol ratio of l to '2 was vaporiie'd;preheated and :passed through 5 a reaction fzonecontaining anvactivemagnesium oxide supportedon pumice, the said magnesia having am-iodinenumber of 130 and an ignition lcssof *7 and? the said, gases beingpassed tatha' velocity of 0-536 literlliter of catalyst/hour;'The-productl=.wa recovered "in the same-manner as described in Example;1. .The amount collected represented- 54% conversion of thephenylvaeeti'c; acidi vPl iI'he supported catalyst mayfbesatistactorilyobtained :by soaking a -.volume. 'orthe. pumice or other carrier-in an 1equal volume. of "magnesium:

nitrate ior "a-peri'od of :30 minutes with constant agitation. ..At theend of thistperiod the aishtpattantelevated:temperatnremtmnwnc:

in the presence of a slow stream of nitrogen passed over the same.

Aceticicid cc vertedinto acetone by ass: ing vapors of the same overmagnesia in a zone maintained at about 345 C. at a rate of 40 mi11i.-"

liters per hour, the amount of from to grams. Whe 4 magnesia wasemployed, the but when a highly active magnesia was employe theconversion was 99.8%.

Example Adipic acid in the molten state maintained in contact withmagnesia in a inolratio of 211-156 until the reaction had gonesubstantially to c tilled over at a. temperature of about 290 C.Thereafter the distillate-was refined by redistillation and a fractionobtained at 1 2 8 to 8 1C-bb ne n ei em ss iv 9: w en acti inagne' iconvrs'i ii t i The 1 active magnesia's contemplated presentinventiomcould be satisfactorily produced by the process of PatentNumber 2,219,726 issued to Seaton- This pa'tehtdi'sjcl e's methodsiodine numbers'andthatactive I V iodine numbersUf'MBahd mare can beproduced by passing a magnesium hydroxide slurry through an inclinedrotary "kilnrountercurrent to hot fiamegases and heating thessame to avery -high pletion. Thereafter the reaction mass was "ais' weretemperature; Qfi,fOreEXamp1eji7813iG. for a brief- HtshEheinfihelosed-is:definedsin. the? article Ac-- hive; magn sia?jhmitwanfithpresent applicants, g

appearing'in. ndeEngtChem,volume.39, page 69. T11? l ltiq lossiOfsuclnproductszmayn beide'fin'edf as; theper cnt, weightalosssobtained byburningfv ar gn e gram sample'cof z theszactive imagnesia in porcelacrueibleiianiaitnufiie furnace at 1000; C13

other materialsiand equivalentvconditior'is which will ocourxtonthoseskilled in" the art upon con 70 sidefa'tion' :ofi the; scope of thetrmstempl'oyedtrin definingrthe "genralzinventio 'ndin the claims?appended hereto; ;We';clain;:1;? .I

,Imthe'production of ketone's from carboxyl denser-elevatedte'mperatursi tlie imprd'vemezie 75 --magn es ium -"hyd'r Y, --'theretoan'itidirihumber in excess of 15 and an 1 being supportedon{aporous'carrier.

which comprises, catalyzing the dehydrocarboxylation reaction bycarrying out the same in the presence of an active magnesia being amagnes-ium oxide magnesium hydroxidezproduct having an.i'odine'n'umbrwin excess; or 15 iarid a'kn ignition loss of from 1 to20% at a temperature below about 350 C.

2. A processv for .t he' production of ketones which... D nt'inuouslypassing vapors of a carbokyli 01 a an elevated temperature beloweaboutf350 fQifiIlfiO contact with an active magnesia. 'comp'" ed of magnesiumoxide and de in proportions imparting nit onqssof. 79 1, 1 to 3" Aprocess for the production of ketones from carboxylic acids at elevatedtemperatures which=comprises passing the carboxylic acids in vapor formthrough active magnesia composed; of-.- magnesium I oxide i andmagnesium -hydroxideHin"-proportions imparting thereto an io-'-dinennum-berr-of :a'itileast and an ignitionlloss I of betWeen:.2 and1'5 %:.=at "a temperature below;

about 35'0}C-.; 4 The process of producing ketones'from car-' boxylicacids which comprises continuously passing vaporsof at least onecarboxylic acid ata temperature ofrfrom 5300 350" C.- into contactwithian active magnesiaconiposedofmagn siumi oxide 'ands magnesiumhydroxide' 'i-n proportions imparting: thereto an iodine-numberexcess"of 15 andan ignition loss of -from -1 to 20%. 5. The proc'ess 'ofproducing mixe' eto' whichrcomprises heating a-mixture'of earboxyli'cacidssto a temperature (Sf-300 t0 350 -CL in C0nfiaCti with-an activemagnesia-composed crmagne'smm oxide and magnesium hydroxide inpioportions'? v we impartingthereto an iodine numbp-m excess snes ashine 15 andanignition loss ofifrom 1'-to'-2o l My 6. a Theprocessor-preparing i pnen'yl cetohe which comprises passingvaporserpnenyraceticg acid and of acetic acid in ex'ces's' n 'elev 'e'dtemperature of about 300'3504 C; over a i'riag nesium'oxiole-ma'gnesiim:-1liydroi tide "product proportions imparting- 'aniodine number in excess-'- of 15 and an ignition loss of froir i l to20%lfie-The process of 1 preparing I ph'enyl acetone which comprisespassingwapors of phenyliacetic' acetonein contact' with an-activemag-meg posed of magnesium oxide 'and maghesm droxide in prop t u a 5thr- I 5H,; acid and. ofacetic 'a'cid tog'ethenwith vapors 6r;

350C I; i. a-

N -':8. The process o producing phenyl-adetonewhichxcomprisespassingvapors-of phenyl aceticacid I and of acetic acid -arr-excessdeanelevated temperature belowabout sso b: magnesia ccmpcseuhf inagh sium oxide and magnesium: hydroxide in propz'jrtior-n fimiria ting theretoaniodine' number-"in excessbf 15 a ignition loss-of from 1 to2 0%; thesaid 9. iTheqprocess of producing p enyi a whichrcomprises passingvapors'f of phenyacid rand'of acetic' acid in" temperature belo'w "about3 theretozf ah iodine gnumber in'eXces's an i'gnitiohvlossof from to20%" nes'ia"beingfsuppoi ted hydroxide in -proportions;

perature oi! from 300 to 350 0. in contact with FOREIGN PATENTS anactive magnesia composed of magnesium oxide Number country Date andmagnesium hydroxide in proportions impart- 494 246 France Sept 3 1919 mgthereto an iodine number in excess of 15 and. an ignition loss of from 1to 20%. 5 OTHER REFERENCES "ALBERT C.ZETTLEMOYER. Blatt: OrganicSyntheses, Collective vol. II, WILLIAMC. WALKER. pp. 389-91 (1943) JohnWiley and Sons, New WILLIAM L. STUMP. Yo k,

Curtis et a1.: J. Soc. Chem. Ind. (London), vol. REFERENCES CITED 10 66,pp. 402-07 (1947); abst. in Chem. Absts., vol. The following referencesare of record in the 3726 (1948)- file 0! this patent: Zettlemoyer etal.: Ind. Eng. Chem vol. 39,

pp. 69-74 (1947). UNITED STATES PAIENTS I Advances in Catalysis, vol. I,pp. 81-82, edited Number Name Date 15 by Frankenburg et al., copyright1948 by Aca- 1904,495 Manger p 1933 demic Press Inc New York 2,219,726588.1301]. Oct. 29, 1940

1. IN THE PRODUCTION OF KETONES FROM CARBOXYLIC ACIDS AT ELEVATEDTEMPERATURES, THE IMPROVEMENT WHICH COMPRISES, CATALYZING THEDEHYDROCARBOXYLATION REACTION BY CARRYING OUT THE SAME IN THE PRESENCEOF AN ACTIVE MAGNESIA BEING A MAGNESIUM OXIDE-MAGNESIUM HYDROXIDEPRODUCT HAVING AN IODINE NUMBER IN EXCESS OF 15 AND AN IGNITION LOSS OFFROM 1 TO 20% AT A TEMPERATURE BELOW ABOUT 350* C.